2003 Blackbird is just over 20,000 miles. I have only done oil changes, a new windscreen, lowered the foot pegs using a member on this forum's custom aluminum mounts, raised the handlebars using VFR handlebars, and put an aftermarket JT 18T front sprocket along with a new DID VZM2 chain, about 500-1000 miles on the new chain/sprocket config.
I notice vibration in the foot pegs most of all, and its very noticeable now. Almost makes my feet fall asleep on longer rides. I noticed that it goes away completely when I pull in the clutch and just coast at any speed. If I'm in say 6th gear doing 45-60mph and give it 1/4 throttle or more it is VERY noticeable, getting worse as more throttle is applied. Even under normal acceleration its almost annoying. Anything over 3,000 RPM. I've had the bike since it had 6,000 miles on it, and I've never noticed it this bad before. In fact, I loved the smooth silky feel it had.
Two things that may be related. Before/during this happened, I was stuck in traffic for about 30-60 minutes, shutting off the engine when I could. I think my temp reached 235-240 before I was able to get to an off-ramp. An hour or so after that I drove through ~3 feet of water (strong current) for about 1/8 mile (closed road due to flooding) which is stupid now that I think of it, but at the time, it was an amazing experience. The water was not so high that it got into the intake. The bike ran fine through it. Wasn't able to go more than 2-4 mph with out the tire breaking loose. Not that I wanted to go any faster.
The vibration I think was slowly getting worse before this though.
I use Mobile 1 MX4T Synthetic oil, changed every 5,000 miles or so.
Any ideas? I don't think its sprocket/drive train related, because it goes away when the clutch is in. I also don't think it is the tires (BT-021) for the same reason.